1. Field of the Invention
The present invention relates to an apparatus that is configured to project a radiation image and a method for the same.
2. Description of the Related Art
Conventionally, film screen systems that combine an intensifying screen and a radiographic film are commonly used as X-ray imaging apparatus in medical facilities. According to this method, X-rays pass through an object, and an intensifying screen converts the X-rays into visible light corresponding to X-ray intensity. Then, radiographic film is exposed to the visible light, thus forming an X-ray image on film.
Physicians perform interpretations by viewing X-ray images formed on the film with a viewing apparatus called a film illuminator (Schaukasten). Furthermore, Japanese Patent Application Laid-Open No. 05-064081 discusses an apparatus that uses an image intensifier, i.e., an image pickup tube that photographs X-rays. The apparatus captures an X-ray image by X-ray radioscopy and displays the X-ray image on a cathode ray tube (CRT) monitor.
Japanese Patent No. 3,066,944 discusses a high-resolution solid X-ray detector that uses a flat panel detector (FPD), i.e., an X-ray detector in a flat-surface form. An object is placed between an X-ray source and an X-ray sensor, and the solid X-ray detector converts X-rays that pass through the object into electrical signals. The X-ray image of the object is converted into electrical signals and captured as digital data. Furthermore, Japanese Patent Application Laid-Open No. 2004-073354 discusses an apparatus that performs X-ray imaging by using a cassette-type portable sensor.
When performing medical procedures such as surgery on a human body at the location of medical treatment, it is sometimes necessary to ascertain an internal structure of the body, especially structures of internal hard tissue and soft tissue. For example, it is necessary to ascertain internal structures during diagnostic imaging of a temporomandibular joint, i.e., a jaw joint, in which a contrast medium is injected into an articular cavity of the temporomandibular joint, and an X-ray image is used for diagnosis. During diagnostic imaging of a temporomandibular joint, a contrast medium is injected by puncturing the skin surface of a patient with a puncture needle. Accurate puncturing with the puncture needle and delivery of the contrast medium to the intended articular cavity are important for performing proper imaging and treatment.
However, puncturing too deep may risk middle cranial fossa damage or penetration through the mandibular fossa capsule to the base of the brain. Due to the complexities regarding articular cavity puncture as described above, a surgeon is required to have extensive anatomical knowledge, experience, and skill.
Furthermore, it is necessary to as certain an internal body structure in other various surgeries as well. Japanese Patent Application Laid-Open No. 2003-275198 discusses a method of ascertaining an internal body structure by projecting an X-ray image onto a half mirror and forming a synthesized image of an object image and the X-ray image on the half mirror.
Japanese Patent Application Laid-Open No. 2003-275198 discusses an apparatus wherein it is necessary to prepare an X-ray image in advance and set the X-ray image into the apparatus. A physician is required to look away from the object to view a half mirror to confirm a synthesized image of an object image and an X-ray image, which makes the operation complex.